1. Field of the Invention
This invention relates to a pneumatic tire for use in four-wheeled vehicles exclusively carrying persons other than goods and cargo, which are known as passenger cars, more particularly this invention relates to an improvement of the cornering stability in this type of the pneumatic tire for passenger cars using a belt composed of steel cords.
2. Description of the Prior Art
In the pneumatic tire comprising a carcass as a reinforcement for a tire casing and a belt composed of two parallel-arranged belt layers each containing steel cords therein, the cords of the layers are crossed with each other with respect to the mid-circumferential line of the tire. The rigidity of the belt is usually high and the cornering stability is excellent over a region extending from a small turning angle to middle turning angle because when a slip angle (hereinafter abbreviated as SA) is given during the running of the tire, the deformation of the belt is small and hence the cornering power (hereinafter abbreviated as Cp) at the small turning angle is large.
However, as Cp becomes larger, the attainment of cornering force (hereinafter abbreviated as CF) to an uppermost peak at a higher SA increases. Hence, the rapid change of CF over a region extending from middle turning angle to large turning angle deteriorates the cornering stability, which is still involved in the tire.